Fluorine-containing compound having hydrolyzable metal alkoxide moiety, curable fluorine-containing polymer prepared from the same compound, and curable fluorine-containing resin composition comprising the same polymer

ABSTRACT

There is provided a material which is free from fading into white due to surface scattering and is useful as a laminated article having excellent adhesion and practical low reflection. A fluorine-containing compound which has a hydrolyzable metal alkoxide moiety and is represented by the formula (1): 
                         
wherein X 1  and X 2  are the same or different, and each is H or F; X 3  is H, F, CH 3  or CF 3 ; X 4  and X 5  are the same or different, and each is H, F or CF 3 ; Rf 1  is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and ether bond, which is an organic group in which 1 to 3 hydrogen atoms are replaced by Y 1  where Y 1  is a functional group having, at its end, at least one hydrolyzable metal alkoxide moiety having 1 to 10 carbon atoms; a is 0 or an integer of 1 to 3; b and c are the same or different, and each is 0 or 1, a curable fluorine-containing polymer obtained from the above-mentioned compound, and a curable fluorine-containing resin composition comprising the polymer.

TECHNICAL FIELD

The present invention relates to a novel fluorine-containing compoundand polymer having a hydrolyzable metal alkoxide moiety, and a curablefluorine-containing resin composition prepared using the polymer.

BACKGROUND ART

In order to enhance visibility of an image of liquid crystal displays(LCD) and the like, measures to inhibit a reflection on the surfacethereof are taken. One of such measures is to provide, on the surface, alight scattering layer having a fine uneven structure giving ananti-glaring property. However, when the light scattering layer isprovided on the surface of LCD, there is a demerit such that surfacescattering arises and when a black color is displayed, the displayedpicture becomes whitish, namely, so-called “fading into white color”arises, which results in lowering of an image contrast.

For making improvement in reducing this “fading into white color”, thereis a method of imparting a reflection reducing ability to preventlowering of an image contrast by providing, on a surface of a resincoating layer having a fine uneven structure, a coating layer having arefractive index lower than that of the resin coating layer (forexample, JP-A10-201043 and JP-A-2003-344614).

However, with respect to a coating layer to be provided on a surface ofa conventional resin coating layer having a fine uneven structure, therehave been proposed only materials having a high refractive index (forexample, not less than 1.40). As a result, a displayed image contrast islowered, and also durability is poor since such a coating layer islacking in adhesion to the light scattering layer which is a substrate.

Such being the case, laminating materials having practical anti-glaringproperty and low reflection in which improvements are made in solvingthe mentioned problems are desired.

DISCLOSURE OF INVENTION

An object of the present invention is to provide a material which isuseful for a laminated article having a practical low reflection, keepsan anti-glaring property, is free from “fading into white color”attributable to surface scattering and is excellent in adhesion.

Namely, the present invention relates to a curable fluorine-containingpolymer (hereinafter referred to as “the first polymer”) having ahydrolyzable metal alkoxide moiety which has a number average molecularweight of from 500 to 1,000,000 and is represented by the formula (2):

M

N

A

  (2)wherein the structural unit M is a structural unit which is derived froma fluorine-containing ethylenic monomer having a hydrolyzable metalalkoxide moiety and is represented by the formula (M):

in which X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf¹ is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y¹ where Y¹ is a functional group containing, at itsend, at least one hydrolyzable metal alkoxide moiety and having 1 to 50carbon atoms; a is 0 or an integer of 1 to 3; b and c are the same ordifferent, and each is 0 or 1,the structural unit N is a structural unit derived from afluorine-containing ethylenic monomer and represented by the formula(N):

in which X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf² is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y² where Y² is a monovalent organic group having 2 to 10carbon atoms and containing, at its end, an ethylenic carbon-carbondouble bond; a is 0 or an integer of 1 to 3; b and c are the same ordifferent, and each is 0 or 1,the structural unit A is a structural unit derived from a monomer beingcopolymerizable with the fluorine-containing ethylenic monomersproviding the structural units represented by the formulae (M) and (N),andthe structural units M, N and A are contained in amounts of from 0.1 to100% by mole, from 0 to 99.9% by mole and from 0 to 99.9% by mole,respectively.

Further the present invention relates to a curable fluorine-containingpolymer (hereinafter referred to as “the second polymer”) having ahydrolyzable metal alkoxide moiety which has a number average molecularweight of from 500 to 1,000,000 and is represented by the formula (2-1):

M

N

A1

A2

  (2-1)wherein the structural unit M is a structural unit which is derived froma fluorine-containing ethylenic monomer having a hydrolyzable metalalkoxide moiety and is represented by the above-described formula (M),the structural unit N is a structural unit which is derived from afluorine-containing ethylenic monomer and is represented by theabove-described formula (N), the structural unit A1 is a structural unitrepresented by the formula (A1):

in which X¹¹, X¹² and X¹³ are the same or different, and each is H or F;X¹⁴ is H, F or CF₃; h is 0 or an integer of 1 or 2; i is 0 or 1; Rf⁴ isa fluorine-containing divalent alkylene group having 1 to 40 carbonatoms or a fluorine-containing divalent alkylene group having 2 to 100carbon atoms and ether bond; Z¹ is a group selected from the groupconsisting of —OH, —CH₂OH, —COOH, a carboxylic acid derivative, —SO₃H, asulfonic acid derivative, an epoxy group and a cyano group, thestructural unit A2 is a structural unit represented by the formula (A2):

in which X¹⁵, X¹⁶ and X¹⁸ are the same or different, and each is H or F;X¹⁷ is H, F or CF₃; h1, i1 and j are the same or different, and each is0 or 1; Z² is H, F, Cl or a linear or branched perfluoroalkyl grouphaving 1 to 16 carbon atoms; Rf⁵ is a fluorine-containing divalentalkylene group having 1 to 20 carbon atoms or a fluorine-containingdivalent alkylene group having 2 to 100 carbon atoms and ether bond, thestructural units M, N, A1 and A2 are contained in amounts of from 0.1 to90% by mole, from 0 to 99.9% by mole, from 0 to 99.9% by mole and from 0to 99.9% by mole, respectively, andN+A1+A2 is contained in an amount of from 10 to 99.9% by mole.

In any of the curable fluorine-containing polymers, it is preferablethat at least one of Y¹ is bonded to the end of Rf¹, and further in thesecond polymer, it is preferable that at least one of Y² is bonded tothe end of Rf².

In the first and second polymers represented by the formulae (2) and(2-1), respectively, the structural unit M is preferably a structuralunit M1 derived from a fluorine-containing ethylenic monomer andrepresented by the formula (M1):

wherein X¹, X², X³, X⁴, X⁵, Rf¹, a and c are as defined above.

Further the structural unit M is preferably a structural unit M2 derivedfrom a fluorine-containing ethylenic monomer and represented by theformula (M2):

wherein Rf¹ is as defined above, or a structural unit M3 derived from afluorine-containing ethylenic monomer and represented by the formula(M3):

wherein Rf¹ is as defined above.

Also in any of the curable fluorine-containing polymers, it ispreferable that Rf¹ is one represented by the formula:—D—Rywherein —D— is a fluoroether unit represented by the formula (D):

O—R

_(n) or

R—O

_(n)  (D)in which n is an integer of 1 to 20; R is at least one selected fromfluorine-containing divalent alkylene groups having 1 to 5 carbon atomswhere at least one of hydrogen atoms is replaced by fluorine atom, and Rmay be the same or different when n is not less than two; Ry is ahydrocarbon group having 1 to 39 carbon atoms where a part or the wholeof hydrogen atoms may be replaced by fluorine atoms, or a hydrocarbongroup having 1 to 99 carbon atoms and ether bond where a part or thewhole of hydrogen atoms may be replaced by fluorine atoms, which is anorganic group in which 1 to 3 hydrogen atoms are replaced by Y¹ (Y¹ isas defined above), and more specifically Ry is preferably a grouprepresented by the formula (Ry):—O—Ry¹  (Ry)wherein Ry¹ is an organic-inorganic complex radical represented by theformula:—(R¹¹)_(p)R¹²—(Y^(1a))_(m)where p is 0 or 1; m is an integer of 1 to 3; R¹¹ is —CONH—; R¹² is adi-, tri- or tetra-valent hydrocarbon group having 1 to 39 carbon atomswhere a part or the whole of hydrogen atoms may be replaced by fluorineatoms or a di-, tri- or tetra-valent hydrocarbon group having 1 to 99carbon atoms and ether bond where a part or the whole of hydrogen atomsmay be replaced by fluorine atoms; Y^(1a) is a functional grouprepresented by the formula:—[M¹O(R²⁹)_(a)(R³⁰)_(b)(R³¹)_(c)(R³²)_(d)]_(n)—M²(R³³)_(e)(R³⁴)_(f)(R³⁵)_(g)(R³⁶)_(h)(R³⁷)_(i)where M¹ and M² are the same or different and each is a di-, tri-,tetra-, penta- or hexa-valent metal atom; a, b, c and d are 0 or 1, anda+b+c+d+2 is equal to the number of valences of the metal atom M¹; e, f,g, h and i are 0 or 1, and e+f+g+h+i+1 is equal to the number ofvalences of the metal atom M²; R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶and R³⁷ are the same or different and each is an organic grouprepresented by the formula OR³⁸ or R³⁸ where R³⁸ is hydrogen atom or ahydrocarbon group having 1 to 10 carbon atoms in which a part or thewhole of hydrogen atoms may be replaced by fluorine atoms, and at leastone of R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶ and R³⁷ is OR³⁸; n is 0 oran integer of 1 to 11.

In the second polymer, it is preferable that the structural unit (A1) isa structural unit represented by the formula (A1-1):

where Rf⁴ and Z¹ are as defined in the formula (A1), or a structuralunit represented by the formula (A1-2):

where Rf⁴ and Z¹ are as defined in the formula (A1), or the structuralunit (A2) is a structural unit derived from at least one monomerselected from the group consisting of tetrafluoroethylene, vinylidenefluoride, chlorotrifluoroethylene and hexafluoropropylene.

The present invention also relates to a curable fluorine-containingresin composition comprising:

(a) the above-described first or second curable fluorine-containingpolymer having a hydrolyzable metal alkoxide moiety, and

(b) a curing agent.

Further the present invention relates to a curable fluorine-containingresin composition for coating comprising:

(a) the above-described first or second curable fluorine-containingpolymer having a hydrolyzable metal alkoxide moiety,

(b) a curing agent, and

(c) a solvent.

By curing those curable compositions, a cured article and cured filmhaving excellent characteristics can be provided.

The fluorine-containing compound which has a hydrolyzable metal alkoxidemoiety, provides the structural unit M of the first and second polymersand is represented by the formula (1):

in which X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf¹ is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y¹ where Y¹ is a functional group containing, at itsend, at least one hydrolyzable metal alkoxide moiety and having 1 to 50carbon atoms; a is 0 or an integer of 1 to 3; b and c are the same ordifferent, and each is 0 or 1, is a novel compound.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] An IR chart of a fluorine-containing allyl ether monomer havinga silicon alkoxide and synthesized in Example 1.

[FIG. 2] An IR chart of a curable fluorine-containing polymer which hasa silicon alkoxide and α-fluoroacryloyl group and is synthesized inExample 3.

BEST MODE FOR CARRYING OUT THE INVENTION

The first polymer of the present invention is the curablefluorine-containing polymer having a hydrolyzable metal alkoxide moietywhich has a number average molecular weight of from 500 to 1,000,000 andis represented by the formula (2):

M

N

A

  (2)wherein the structural unit M is a structural unit having a hydrolyzablemetal alkoxide moiety, the structural unit N is a structural unit havingan ethylenic carbon-carbon double bond and the structural unit A is anoptional structural unit, and the structural units M, N and A arecontained in amounts of from 0.1 to 100% by mole, from 0 to 99.9% bymole and from 0 to 99.9% by mole, respectively.

Then each structural unit is explained below.

The structural unit M is the structural unit which is derived from afluorine-containing ethylenic monomer having a hydrolyzable metalalkoxide moiety and is represented by the formula (M):

in which X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf¹ is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y¹ where Y¹ is a functional group containing, at itsend, at least one hydrolyzable metal alkoxide moiety and having 1 to 50carbon atoms; a is 0 or an integer of 1 to 3; b and c are the same ordifferent, and each is 0 or 1.

The structural unit M is particularly preferably the structural unit M1derived from a fluorine-containing ethylenic monomer and represented bythe formula (M1):

wherein X¹, X², X³, X⁴, X⁵, Rf¹, a and c are as defined above.

The fluorine-containing polymer having this structural unit M1 ispreferable because particularly a refractive index is low, adhesion tovarious substrates such as a light scattering layer is good anddurability can be enhanced.

Further one of more preferable examples of the structural unit M1 is thestructural unit M2 derived from a fluorine-containing ethylenic monomerand represented by the formula (M2):

wherein Rf¹ is as defined above.

This structural unit M2 is preferable because a refractive index is low,adhesion to various substrates such as a light scattering layer is good,durability can be enhanced, and in addition, copolymerizability withother fluorine-containing ethylenic monomers is good.

Also other preferable example of the structural unit M1 is thestructural unit M3 derived from a fluorine-containing ethylenic monomerand represented by the formula (M3):

wherein Rf¹ is as defined above.

This structural unit M3 is preferable because a refractive index is low,adhesion to various substrates such as a light scattering layer is good,durability can be enhanced, and in addition, copolymerizability withother fluorine-containing ethylenic monomers is good.

In the present invention, Rf¹ contained in the structural units M, M1,M2 and M3 is, as described above, an organic group having 1 to 3functional groups Y¹ which contains, at its end, at least onehydrolyzable metal alkoxide moiety and has 1 to 50 carbon atoms, and anupper limit of the number of carbon atoms is preferably 30, morepreferably 20, particularly preferably 10.

The hydrolyzable metal alkoxide moiety in the Y¹ functions to cause ahydrolysis and polycondensation reaction, thereby exhibiting an effectof enhancing good adhesion durability with a substrate having hydroxylgroup.

It is preferable that Rf¹ is one represented by the formula (Rf1):—D—Ry  (Rf1)wherein —D— is a fluoroether unit represented by the formula (D):

O—R

_(n) or

R—O

_(n)  (D)in which n is an integer of 1 to 20; R is at least one selected fromfluorine-containing divalent alkylene groups having 1 to 5 carbon atomswhere at least one of hydrogen atoms is replaced by fluorine atom, and Rmay be the same or different when n is not less than two; Ry is ahydrocarbon group having 1 to 39 carbon atoms where a part or the wholeof hydrogen atoms may be replaced by fluorine atoms or a hydrocarbongroup having 1 to 99 carbon atoms and ether bond where a part or thewhole of hydrogen atoms may be replaced by fluorine atoms, which is anorganic group in which 1 to 3 hydrogen atoms are replaced by Y¹ (Y¹ isas defined above).

—R— is a fluorine-containing divalent alkylene group having 1 to 5carbon atoms and has at least one fluorine atom, thereby being capableof contributing to further lowering of a viscosity of the compound,enhancement of heat resistance, lowering of a refractive index andenhancement of solubility in general purpose solvents as compared withconventional compounds having an alkylene ether unit or an alkoxyl grouphaving no fluorine atom.

Examples of —(O—R)— or —(R—O)— in —D— are —(OCF₂CF₂CF₂)—, —(CF₂CF₂CF₂₀)——(CF₂CF₂CF₂O)—, —(OCFQ¹CF₂)—, —(OCF₂CFQ¹)—, —(OCFQ²)—, —(CFQ²O)—,—(OCH₂CF₂CF₂)—, (OCF₂CF₂CH₂)—, —(OCH₂CH₂CF₂)—, —(OCF₂CH₂CH₂)—,—(OCF₂CF₂CF₂CF₂)—, —(CF₂CF₂CF₂CF₂₀)— —(CF₂CF₂CF₂CF₂O)—, —(OCFQ²CH₂)—,—(CH₂CFQ²O)—, —(OCH(CH₃)CF₂CF₂)—, —(OCF₂CF₂CH(CH₃))—, —(OCQ³ ₂)—, —(CQ³₂O)—, and the like, where Q¹ and Q² are the same or different and eachis H, F or CF₃; Q³ is CF₃. It is preferable that —D— is a repeating unitcomprising one kind or two or more kinds thereof.

Specifically it is preferable that —D— is a repeating unit comprisingone kind or two or more kinds selected from —(OCFQ¹CF₂)—,—(OCF₂CF₂CF₂)—, —(OCH₂CF₂CF₂)—, —(OCFQ²)—, —(OCQ³ ₂)—, —(CFQ¹CF₂O)—,—(CF₂CF₂CF₂O)—, —(CH₂CF₂CF₂₀)— —(CH₂CF₂CF₂O)—, —(CFQ²O)— and —(CQ³ ₂O)—,particularly preferably a repeating unit comprising one kind or two ormore kinds selected from —(OCFQ¹CF₂)—, —(OCF₂CF₂CF₂)—, —(OCH₂CF₂CF₂)—,—(CFQ¹CF₂O)—, —(CF₂CF₂CF₂O)— and —(CH₂CF₂CF₂O)—, further preferably arepeating unit comprising one kind or two or more kinds selected from—(OCFQ¹CF₂)—, —(OCF₂CF₂CF₂)—, —(CFQ¹CF₂O)— and —(CF₂CF₂CF₂O)—.

It is to be noted that the —O—O— structural unit (specifically—R—O—O—R—, —O—O—R—, —R—O—O— or the like) is not contained in the abovedescribed fluorine-containing ether unit —D— and the above describedRf¹.

In the formula (Rf1), Ry is preferably a group represented by theformula (Ry):—O—Ry¹  (Ry)wherein Ry¹ is an organic-inorganic complex radical represented by theformula (Ry1):—(R¹¹)_(p)R¹²—(Y^(1a))_(m)  (Ry1)where p is 0 or 1; m is an integer of 1 to 3; R¹¹ is —CONH—; R¹² is adi-, tri- or tetra-valent hydrocarbon group having 1 to 39 carbon atomswhere a part or the whole of hydrogen atoms may be replaced by fluorineatoms or a di-, tri- or tetra-valent hydrocarbon group having 1 to 99carbon atoms and ether bond where a part or the whole of hydrogen atomsmay be replaced by fluorine atoms; Y^(1a) is a functional grouprepresented by the formula:—[M¹O(R²⁹)_(a)(R³⁰)_(b)(R³¹)_(c)(R³²)_(d)]_(n)—M²(R³³)_(e)(R³⁴)_(f)(R³⁵)_(g)(R³⁶)_(h)(R³⁷)_(i)where M¹ and M² are the same or different and each is a di-, tri-,tetra-, penta- or hexa-valent metal atom; a, b, c and d are 0 or 1, anda+b+c+d+2 is equal to the number of valences of the metal atom M¹; e, f,g, h and i are 0 or 1, and e+f+g+h+i+1 is equal to the number ofvalences of the metal atom M²; R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶and R³⁷ are the same or different and each is an organic grouprepresented by the formula: OR³⁸ or R³⁸ where R³⁸ is hydrogen atom or ahydrocarbon group having 1 to 10 carbon atoms in which a part or thewhole of hydrogen atoms may be replaced by fluorine atoms, and at leastone of R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶ and R³⁷ is OR³⁸; n is 0 oran integer of 1 to 11.

In the formula (Ry1), when p is 0, the end of Ry becomes an ether bond,and when p is 1, the end of Ry becomes a urethane bond.

Examples of —R¹²— in the formula (Ry1) are, for instance, as follows.

(in the above described groups, m: 0 to 10, n: 0 to 5, m+n: 1 to 15)

(in the above described groups, l: 1 to 10, m: 1 to 10, n: 0 to 5)

(in the above described groups, each of X³⁰ and X³³ is F or CF₃; each ofX³¹ and X³² is H or F; o+p+q is 1 to 30; r is 0 or 1; sand tare s and tare 0 or 1),and the like.

Examples of the metals M¹ and M² in Y^(1a) are Cu as the IB group; Ca,Sr and Ba as the IIA group; Zn as the IIB group; B, Al and Ga as theIIIA group; Y as the IIIB group; Si and Ge as the IVA group; Pb as theIVB group; P and Sb as the VA group; V and Ta as the VB group; W as theVIB group; and La and Nd as the lanthanide.

Specifically metals of the IVA group, especially Si are preferable asY^(1a), and especially —Si(OCH₃)₃, —Si(OC₂H₅)₃, —SiCH₃(OC₂H₅)₂ and thelike are preferable from the viewpoint of good adhesion to a substratehaving hydroxyl group and durability after hydrolysis andpolycondensation, and also —[SiO(OCH₃)₂]_(n)—Si(OCH₃)₃,—[SiO(OC₂H₅)₂]_(n)—Si(OC₂H₅)₃ and the like, where n is an integer of 1to 11, are preferable from the viewpoint of enhancement of surfacehardness in addition to good adhesion to a substrate having hydroxylgroup and durability thereof after hydrolysis and polycondensation.

Of the above described groups, —Si(OCH₃)₃, —Si(OC₂H₅)₃, —SiCH₃(OC₂H₅)₂and the like are particularly preferable as Y^(1a).

With respect to the metals other than the IVA group, examples of Y^(1a)are:

Ca of the IIA group: —Ca(OR³⁹), and a suitable example is —Ca(OCH₃);

Zn of the IIB group: —Zn(OR³⁹), and a suitable example is —Zn(OC₂H₅);

B of the IIIA group: —B(OR³⁹)₂, and a suitable example is —B(OCH₃)₂;

Y of the IIIB group: —Y(OR³⁹)₂, and a suitable example is —Y(OC₄H₉)₂;

Pb of the IVB group: —Pb(OR³⁹)₃, and a suitable example is —Pb(OC₄H₉)₃;

Ta of the VB group: —Ta(OR³⁹)₄, and a suitable example is —Ta(OC₃H₇)₄;

W of the VIB group: —W(OR³⁹)₅, and a suitable example is —W(OC₂H₅)₅;

La of the lanthanide: —La(OR³⁹)₂, and a suitable example is —La(OC₃H₇)₂;

and the like, wherein R³⁹ is a hydrocarbon group having 1 to 10 carbonatoms in which a part or the whole of hydrogen atoms may be replaced byfluorine atoms.

These various metals may be used in a combination of not only metals ofthe same kind but also metals of different kinds.

The structural unit M is preferably the structural unit M1, and thestructural unit M1 is preferably the structural unit M2 or thestructural unit M3. When —Rf¹ is represented by —D—Ry, the structuralunit M is preferably the structural unit represented by the formula(2-2):

wherein X¹, X², X³, X⁴, X⁵, D, Ry, a, b and c are as defined above, fromthe viewpoint of decreasing a refractive index and a viscosity and alsofrom the viewpoint of excellent adhesion durability to a substratehaving hydroxyl group and heat resistance.

Specific examples of the structural unit M1 of the formula (2-2) are:

and the like, and from the viewpoint of excellent heat resistance andchemical resistance, it is particularly preferable that the structuralunit of the formula (2-2) is a structural unit represented by theformula (2-3):

wherein X¹, X², X³, X⁴, X⁵, D, Ry, a and c are as defined above.

More specific examples of the structural unit of the formula (2-3) arepreferably:

and the like, and particularly preferable are the structural units suchas:

from the viewpoint of heat resistance and chemical resistance.

The structural unit N is an optional structural unit which is derivedfrom a fluorine-containing ethylenic monomer and is represented by theformula (N):

wherein X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf² is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y² where Y² is a monovalent organic group having 2 to 10carbon atoms and containing, at its end, an ethylenic carbon-carbondouble bond; a is 0 or an integer of 1 to 3; b and c are the same ordifferent, and each is 0 or 1.

It is particularly preferable that the structural unit N is a structuralunit N1 derived from a fluorine-containing ethylenic monomer andrepresented by the formula (N1):

wherein X¹, X², X³, X⁴, X⁵, Rf², a and c are as defined above.

The fluorine-containing polymer having this structural unit N1 ispreferable because a curing reactivity by contact with a radical or acation can be enhanced.

Further one of more preferable examples of the structural unit N1 is astructural unit N2 derived from a fluorine-containing ethylenic monomerand represented by the formula (N2):

wherein Rf² is as defined above.

This structural unit N2 is a structural unit of a fluorine-containingallyl ether having an ethylenic carbon-carbon double bond at its end,and is preferable because not only near infrared transparency can beenhanced but also a refractive index can be decreased, and alsopolymerizability is good and copolymerizability with otherfluorine-containing ethylenic monomers is satisfactory.

An another preferable example of the structural unit N1 is a structuralunit N3 derived from a fluorine-containing ethylenic monomer andrepresented by the formula (N3):

wherein Rf² is as defined above.

This structural unit N3 is a structural unit of a fluorine-containingvinyl ether having an ethylenic carbon-carbon double bond at its end,and is preferable because not only near infrared transparency can beenhanced but also a refractive index can be decreased, and alsocopolymerizability with other fluorine-containing ethylenic monomers issatisfactory.

The Y² contained in the structural units N, N1, N2 and N3 is, asdescribed supra, a monovalent organic group having 2 to 10 carbon atomsand containing an ethylenic carbon-carbon double bond at its end.

This carbon-carbon double bond contained in the Y² has an ability ofcausing a polycondensation reaction, and can provide a cured(crosslinked) article. Specifically a polymerization reaction or acondensation reaction is caused between the fluorine-containing polymermolecules or between the fluorine-containing polymer and the curing(crosslinking) agent to be added as case demands, for example, by acontact with a radical or a cation, and thereby a cured (crosslinked)article can be provided.

The first preferable Y² is:

O

_(d)

C═O

_(e)Y^(2a)wherein Y^(2a) is an alkenyl group or fluorine-containing alkenyl grouphaving 2 to 5 carbon atoms and containing an ethylenic carbon-carbondouble bond at its end; d and e are the same or different and each is 0or 1.

A preferable example of Y^(2a) is:—CX⁶═CX⁷X⁸wherein X⁶ is H, F, CH₃ or CF₃; X⁷ and X⁸ are the same or different andeach is H or F, and this group is preferable because a curing reactivityby a contact with a radical or a cation is high.

Preferable examples of Y^(2a) are:

and the like.

A more preferable example of Y² is:—O(C═O)CX⁶═CX⁷X⁸wherein X⁶ is H, F, CH₃ or CF₃; X⁷ and X⁸ are the same or different andeach is H or F, and this group is preferable because a curing reactivityby a contact with a radical is high and a cured article can be obtainedeasily by photo-curing.

Examples of the more preferable Y² described above are:

and the like.

Examples of other preferable Y² are:

and the like.

Of the groups Y², those having a structure of —O(C═O)CF═CH₂ arepreferable because near infrared transparency can be enhanced, a curing(crosslinking) reactivity is especially high and a cured article can beobtained efficiently.

The above described organic group Y² having a carbon-carbon double bondin its side chain may be introduced into the end of the polymer trunkchain.

In the fluorine-containing polymer used in the present invention, —Rf²—(a group obtained by removing Y² from the mentioned —Rf²) contained inthe structural units N, N1, N2 and N3 is a fluorine-containing alkylenegroup having 1 to 40 carbon atoms or a fluorine-containing alkylenegroup having 2 to 100 carbon atoms and ether bond. In this Rf² group, afluorine atom is to be bonded to the carbon atom contained therein, andis generally a fluorine-containing alkylene group or afluorine-containing alkylene group having ether bond, in which afluorine atom and hydrogen atom or a chlorine atom are bonded to thecarbon atom. Preferable is the Rf² containing more fluorine atoms (ahigh fluorine content), and more preferable is a perfluoroalkylene groupor a perfluoroalkylene group having ether bond. The fluorine content ofthe fluorine-containing polymer is not less than 25% by mass, preferablynot less than 40% by mass. This fluorine content is preferable becausenot only a near infrared transparency of the fluorine-containing polymercan be enhanced but also a refractive index thereof can be decreased,and even if a curing degree (crosslinking density) is increasedparticularly for the purpose of enhancing heat resistance and elasticmodulus of a cured article, a near infrared transparency can bemaintained high or a refractive index can be maintained low.

When the number of carbon atoms of the —Rf²— group is too large, in thecase of fluorine-containing alkylene groups, in some cases, solubilityin a solvent is lowered and transparency is lowered, and in the case offluorine-containing alkylene groups having ether bond, in some cases, ahardness and mechanical characteristics of the polymer itself and thecured article obtained therefrom are lowered. Therefore too large numberof carbon atoms is not preferable. The number of carbon atoms offluorine-containing alkylene groups is preferably 1 to 20, morepreferably 1 to 10, and the number of carbon atoms offluorine-containing alkylene groups having ether bond is preferably 2 to30, more preferably 2 to 20.

Preferable examples of —Rf²— are:

(In the above described groups, m: 0 to 10, n: 0 to 5)

(in the above described groups, l: 1 to 10, m: 1 to 10, n: 0 to 5)

(In the above described groups, each of X³⁴ and X³⁷ is F or CF₃; each ofX³⁵ and X³⁶ is H or F; o+p+q is 1 to 30; r is 0 or 1; sand tare s and tare 0 or 1),and the like.

As described above, the structural unit N constituting thefluorine-containing polymer used in the present invention is preferablythe structural unit N1, and further the structural unit N1 is preferablythe structural unit N2 or the structural unit N3. Then examples of thestructural unit N2 and the structural unit N3 are explained below.

Preferable examples of the monomers constituting the structural unit N2are:

wherein n is an integer of 1 to 30; Y² is as defined above.

More specific examples thereof are:

and the like, wherein Rf⁷ and Rf⁸ are perfluoroalkyl groups having 1 to5 carbon atoms; n is 0 or an integer of 1 to 30; X is H, CH₃, F or CF₃.

Preferable examples of the monomers constituting the structural unit N3are:

and the like, wherein Y² is as defined above; n is an integer of 1 to30.

More specific examples thereof are:

and the like, wherein Rf⁹ and Rf¹⁰ are perfluoroalkyl groups having 1 to5 carbon atoms; m is 0 or an integer of 1 to 30; n is an integer of 1 to3; X is H, CH₃, F or CF₃.

Preferable examples of monomers constituting the structural unit N ofthe fluorine-containing polymer other than the structural unit N2 and N3are, for instance,

and the like, wherein Y² and Rf² are as exemplified above.

More specific examples thereof are:

and the like, wherein Y² is as defined above.

The structural unit A is a structural unit derived from a monomercopolymerizable with the fluorine-containing ethylenic monomersproviding the structural units represented by the formulae (M) and (N).The structural unit A is an optional component and is not limited aslong as it is a monomer copolymerizable with the structural units M andN. The structural unit A may be optionally selected depending onintended applications of the fluorine-containing polymer and the curedarticle obtained therefrom and required characteristics.

Examples of the structural unit A are, for instance, the followingstructural units.

(A1) Structural Units Derived from Fluorine-Containing EthylenicMonomers Having Functional Group

These structural units (A1) are preferable because adhesion of thefluorine-containing polymer and the cured article thereof to a substrateand solubility in a solvent, particularly in general purpose solventscan be imparted and also because functions such as crosslinkability canbe imparted.

Preferred structural units A1 of the fluorine-containing ethylenicmonomer having functional group are structural units represented by theformula (A1):

wherein X¹¹, X¹² and X¹³ are the same or different and each is H or F;X¹⁴ is H, F or CF₃; h is 0 or an integer of 1 or 2; i is 0 or 1; Rf⁴ isa fluorine-containing divalent alkylene group having 1 to 40 carbonatoms or a fluorine-containing divalent alkylene group having 2 to 100carbon atoms and ether bond; Z¹ is a functional group selected from thegroup consisting of —OH, CH₂OH, —COOH, a carboxylic acid derivative,—SO₃H, a sulfonic acid derivative, an epoxy group and a cyano group, andparticularly preferred are structural units which are derived from:CH₂═CFCF₂ORf⁴—Z¹wherein Rf⁴ and Z¹ are as defined above, and are represented by theformula (A1-1):

wherein Rf⁴ and Z¹ are as defined in the formula (A1).

Specific examples thereof are preferably structural units derived fromfluorine-containing ethylenic monomers such as:

wherein Z¹ is as defined above.

Also there is preferably exemplified a structural unit which is derivedfrom:CF₂═CFORf⁴—Z¹wherein Rf⁴ and Z¹ are as defined above, and is represented by theformula (A1-2):

where Rf⁴ and Z¹ are as defined in the formula (A1).

Specific examples thereof are structural units derived from monomerssuch as:

wherein Z¹ is as defined above.

Other examples of the fluorine-containing ethylenic monomer havingfunctional group are:

CF₂═CFCF₂—O—Rf²—Z¹, CF₂═CF—Rf²—Z¹,

CH₂═CH—Rf²—Z¹, CH₂═CHO—Rf²—Z¹

and the like, wherein —Rf²— is the same as the above described —Rf²— andZ¹ is as defined above. More specifically there are:

and the like, wherein Z¹ is as defined above.(A2) Structural Units Derived from Fluorine-Containing EthylenicMonomers Having no Functional Group

These structural units A2 are preferable from the point that arefractive index of the fluorine-containing polymer and the curedarticle obtained therefrom can be maintained low and because arefractive index can be further decreased. Also these structural unitsare preferable from the point that by selecting the monomer, mechanicalcharacteristics and glass transition temperature of the polymer can beadjusted, and particularly the glass transition temperature can beincreased by copolymerization with the structural units M and N.

Examples of the preferred structural units (A2) of thefluorine-containing ethylenic monomer are those represented by theformula (A2):

wherein X¹⁵, X¹⁶ and X¹⁸ are the same or different and each is H or F;X¹⁷ is H, F or CF₃; h1, i1 and j are the same or different and each is 0or 1; Z² is H, F, Cl or a linear or branched perfluoroalkyl group having1 to 16 carbon atoms; Rf⁵ is a fluorine-containing divalent alkylenegroup having 1 to 20 carbon atoms or a fluorine-containing divalentalkylene group having 2 to 100 carbon atoms and ether bond.

Examples thereof are preferably structural units derived from monomerssuch as:

CH₂═CF

CF₂

_(n)Z² (Z² is as defined in the formula (A2), n is from 1 to 10) andCH₂═CHOCH₂

CF₂

_(n)Z² (Z² is as defined in the formula (A2), n is from 1 to 10).

It is particularly preferable that these structural units are structuralunits derived from at least one monomer selected from the groupconsisting of tetrafluoroethylene, vinylidene fluoride,chlorotrifluoroethylene and hexafluoropropylene because a refractiveindex of the curable fluorine-containing polymer and the cured articleobtained therefrom can be maintained low.

(A3) Fluorine-Containing Aliphatic Ring Structural Units

Introduction of these structural units A3 is preferable sincetransparency can be increased, and also the fluorine-containing polymerhaving a high glass transition temperature can be obtained and a higherhardness of the cured article can be expected.

Examples of the preferred fluorine-containing aliphatic ring structuralunit A3 are those represented by the formula (A3):

wherein X¹⁹, X²⁰, X²³, X²⁴, X²⁵ and X²⁶ are the same or different andeach is H or F; X²¹ and X²² are the same or different and each is H, F,Cl or CF₃; Rf⁶ is a fluorine-containing alkylene group having 1 to 10carbon atoms or a fluorine-containing alkylene group having 2 to 10carbon atoms and ether bond; n2 is 0 or an integer of from 1 to 3; n1,n3, n4 and n5 are the same or different and each is 0 or 1.

For example, there are structural units represented by:

wherein Rf⁶, X²¹ and X²² are as defined above.

Specifically there are:

and the like wherein X¹⁹, X²⁰, X²³ and X²⁴ are as defined above.

Other examples of the fluorine-containing aliphatic ring structuralunits are, for instance,

and the like.(A4) Structural Units Derived from Ethylenic Monomers Having no Fluorine

The introduction of those structural units A4 can enhance solubility ingeneral-purpose solvents and can improve compatibility with additives,for example, a photocatalyst and a curing agent to be added as casedemands.

Examples of the non-fluorine-containing ethylenic monomer are asfollows.

α-Olefins:

Ethylene, propylene, butene, vinyl chloride, vinylidene chloride and thelike.

Vinyl Ether or Vinyl Ester Monomers:

CH₂═CHOR, CH₂═CHOCOR (R: hydrocarbon group having 1 to 20 carbon atoms)and the like.

Allyl Monomers:

CH₂═CHCH₂Cl, CH₂═CHCH₂OH, CH₂═CHCH₂COOH, CH₂═CHCH₂Br and the like.

Allyl Ether Monomers:

CH₂⊚CHCH₂OR CH₂═CHCH₂OR

(R: hydrocarbon group having 1 to 20 carbon atoms),

and the like.Acrylic or Methacrylic Monomers:

Acrylic acid, methacrylic acid, acrylic esters, methacrylic acid esters,maleic anhydride, maleic acid, maleic acid esters and the like.

Monomers obtained by replacing a part or the whole of hydrogen atoms ofthose non-fluorine-containing ethylenic monomers with heavy hydrogenatoms are more preferred from the viewpoint of transparency.

(A5) Structural Units Derived from Alicyclic Monomers

The structural unit A5 of an alicyclic monomer may be introduced as acomponent copolymerizable with the structural units M and N, morepreferably as the third component in addition to the structural units Mand N and the structural unit of the above-mentioned fluorine-containingethylenic monomer or non-fluorine-containing ethylenic monomer (theabove-mentioned A3 or A4), thereby making a glass transition temperatureand a hardness high.

Examples of the alicyclic monomer A5 are norbornene derivativesrepresented by:

wherein m is 0 or an integer of from 1 to 3; A, B, C and D are the sameor different and each is H, F, Cl, COOH, CH₂OH, a perfluoroalkyl grouphaving 1 to 5 carbon atoms or the like, alicyclic monomers such as:

and derivatives thereof to which a substituent is introduced.

The first fluorine-containing polymer may be a homopolymer of thestructural unit M or may be a copolymer of the structural unit M withthe structural unit N and further the structural unit A.

The homopolymer is advantageous from the point that a refractive indexcan be maintained low, functions of imparting a near infraredtransparency and adhesion durability to a substrate having hydroxylgroup can be imparted, and further a high hardness of a coating film canbe obtained.

Also in the case of the copolymer, the content of the structural unit Mmay be not less than 0.1% by mole based on the whole structural unitsconstituting the fluorine-containing polymer, and it is preferable thatthe content is not less than 2.0% by mole, preferably not less than 5%by mole, more preferably not less than 10% by mole in order to obtain acured article having a high hardness by curing (crosslinking) andexcellent abrasion resistance, scratch resistance, chemical resistanceand solvent resistance.

Particularly in applications requiring formation of a cured coating filmbeing excellent in heat resistance and transparency and low in waterabsorption, the content of the structural unit M is not less than 10% bymole, preferably not less than 20% by mole, further preferably not lessthan 30% by mole, particularly preferably not less than 40% by mole. Anupper limit thereof is less than 100% by mole.

A molecular weight, for example, a number average molecular weight ofthe fluorine-containing polymer can be selected within a range from 500to 1,000,000, preferably from 1,000 to 500,000, particularly from 2,000to 200,000.

If the molecular weight is too low, mechanical properties tend to beinsufficient even after the curing, and particularly a cured article anda cured coating film tend to be fragile and insufficient in strength. Ifthe molecular weight is too high, solubility in a solvent is lowered,particularly film forming property and leveling property are apt to belowered at forming a thin film and storage stability of thefluorine-containing polymer tends to be unstable. The number averagemolecular weight is most preferably selected within a range from 5,000to 100,000.

The second polymer of the present invention is a curablefluorine-containing polymer having a hydrolyzable metal alkoxide moietywhich has a number average molecular weight of from 500 to 1,000,000 andis represented by the formula (2-1):

M

N

A1

A2

  (2-1)wherein the structural unit M and the structural unit N are the same asin the first polymer and the structural unit A1 and the structural unitA2 are as defined above,the structural units M, N, A1 and A2 are contained in amounts of from0.1 to 90% by mole, from 0 to 99.9% by mole, from 0 to 99.9% by mole andfrom 0 to 99.9% by mole, respectively, andN+A1+A2 is contained in an amount of from 10 to 99.9% by mole.

The content of the structural unit M in the second fluorine-containingpolymer is not less than 0.1% by mole based on the whole structuralunits constituting the fluorine-containing polymer. In order to obtain acured article having a high hardness by curing (crosslinking) andexcellent abrasion resistance, scratch resistance, chemical resistanceand solvent resistance, it is preferable that the content is not lessthan 2.0% by mole, preferably not less than 5% by mole, more preferablynot less than 10% by mole. Particularly in applications requiringformation of a cured film having excellent heat resistance andtransparency and low water absorption, it is preferable that the contentis not less than 10% by mole, preferably not less than 20% by mole, morepreferably not less than 50% by mole. An upper limit of the content isless than 100% by mole.

The contents of the structural units N, A1 and A2 are each not more than99.9% by mole. The total percent by mole of N+A1+A2 is from 10 to 99.9%by mole. When the total percent by mole is less than 10% by mole, arefractive index cannot be maintained low, and further a hardness of thecured film after the curing tends to become low, which is notpreferable. A more preferable total percent by mole of N+A1+A2 is notless than 20% by mole, further preferably not less than 30% by mole, andnot more than 60% by mole, further preferably not more than 50% by mole.

From the viewpoint that a strength and abrasion resistance of a curedfilm after the curing can be enhanced, a molar ratio (N/(N+A1+A2)) ofthe structural unit N to the sum of the structural units N, A1 and A2 inthe second fluorine-containing polymer is preferably 1/100 to 100/100,more preferably 30/100 to 100/100, further preferably 50/100 to 100/100,particularly preferably 70/100 to 100/100.

Further from the viewpoint that adhesion of a cured film to a substrateand durability thereof can be enhanced, a molar ratio (A1/(N+A1+A2)) ofthe structural unit A1 to the sum of the structural units N, A1 and A2in the second fluorine-containing polymer is preferably 1/100 to 50/100,more preferably 1/100 to 40/100, further preferably 1/100 to 30/100.

A molecular weight, for example, a number average molecular weight ofthe second fluorine-containing polymer can be selected within a rangefrom 500 to 1,000,000, preferably from 1,000 to 500,000, particularlypreferably from 2,000 to 200,000.

If the molecular weight is too low, mechanical properties tend to beinsufficient even after the curing, and particularly a cured article anda cured coating film tend to be fragile and insufficient in a strength.If the molecular weight is too high, solubility in a solvent is lowered,particularly film forming property and leveling property are apt to belowered at forming a thin film, and storage stability of thefluorine-containing polymer tends to be lowered. The number averagemolecular weight is most preferably selected within a range from 5,000to 100,000.

As mentioned above, it can be said that the second polymer comprises, asessential structural units, the structural unit N and/or the structuralunit A which are optional structural units of the first polymer, and isspecifically so defined.

In the second fluorine-containing polymer of the present invention, withrespect to combinations and proportions of the structural unit M (M1, M2and M3), the structural unit N(N1, N2 and N3), and further thestructural unit A (A1 and A2), various combinations of the structuralunit M, the structural unit N and the structural unit A can be selectedfrom the above described examples, depending on intended applications,physical properties (particularly glass transition temperature,hardness, etc.), functions (transparency) and the like.

Also the fluorine-containing polymer is preferably soluble in generalpurpose solvents, for example, in at least one of ketone solvents,acetic acid ester solvents, alcohol solvents and aromatic solvents or insolvent mixtures containing at least one of general purpose solvents.

The fluorine-containing polymer being soluble in general purposesolvents is preferable because film forming property and homogeneity areexcellent particularly in forming a thin film having a thickness of notmore than 0.3 μm 3 μm, for example, of the order of 0.1 μm in a processfor forming a coating film, and also is advantageous from the viewpointof productivity.

For obtaining the fluorine-containing polymer of the present invention,generally any of the following methods can be adopted.

(1) A method of previously synthesizing a monomer having Rf¹ and thenpolymerizing the monomer

(2) A method of once synthesizing a polymer having another functionalgroup and then converting the functional group through polymer reaction,thus introducing the functional group Rf¹ to the polymer

(3) A method of introduction by both of the methods (1) and (2)

Of these methods, the method of (3) is preferable because the curablefluorine-containing polymer of the present invention having ahydrolyzable metal alkoxide moiety is obtained without a curing reactionof the carbon-carbon double bond at an end of a side chain of thefluorine-containing polymer.

For the polymerization, radical polymerization method, anionicpolymerization method, cationic polymerization method and the like canbe employed. Of these methods, the radical polymerization method isparticularly preferable because in the case of the monomers exemplifiedfor obtaining the polymer having a hydrolyzable metal alkoxide moiety,it is easy to control quality of the polymer such as a composition and amolecular weight and produce the polymer on an industrial scale.

The fluorine-containing ethylenic monomer providing the structural unitM, namely the fluorine-containing compound having a hydrolyzable metalalkoxide moiety and represented by the formula (1):

wherein X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf¹ is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y¹ where Y¹ is a functional group containing, at itsend, at least one hydrolyzable metal alkoxide moiety and having 1 to 50carbon atoms; a is 0 or an integer of 1 to 3; b and c are the same ordifferent, and each is 0 or 1, is a novel compound.

A means of initiating the polymerization of such a novelfluorine-containing compound is not limited particularly as long as thepolymerization proceeds radically. The polymerization is initiated, forexample, with an organic or inorganic radical polymerization initiator,heat, light, ionizing radiation or the like. The polymerization can becarried out by solution polymerization, bulk polymerization, suspensionpolymerization, emulsion polymerization or the like.

In this novel fluorine-containing compound, the preferable examples ofthe structural unit M1, M2 and M3 explained supra and Ry and Y¹explained specifically in Rf¹ are also used.

The present invention also relates to the curable fluorine-containingresin composition comprising:

(a) the first or second curable fluorine-containing polymer having ahydrolyzable metal alkoxide moiety, and

(b) a curing agent.

As the curing agent (b), thermally curable or two-component cold curingagents in addition to active energy curing initiators can be used, andactive energy curing initiators are preferable because the compositionis applicable to, for example, transparent resin substrates since acuring reaction can be carried out at relatively low temperatures.

The active energy curing initiator is a compound which generates aradical or a cation (acid) only by irradiation of active energy rayssuch as electromagnetic wave having a wavelength of not more than 350nm, namely ultraviolet ray, electron beam, X-ray or γ-ray, and functionsas a catalyst for initiating the curing (crosslinking reaction) of thecrosslinkable group (for example, carbon-carbon double bond) of thefluorine-containing prepolymer. Usually, initiators generating a radicalor a cation (acid) by means of ultraviolet ray, particularly thosegenerating a radical are used.

According to the curable fluorine-containing resin composition of thepresent invention, since a curing reaction can be initiated easily withthe above described active energy rays, heating at high temperature isnot necessary, and a curing reaction can be carried out at relativelylow temperature. Therefore, the composition is preferable since it isapplicable to substrates, for example, even transparent resin substrateswhich have low heat resistance and are easily subject to deformation,decomposition and coloration with heat.

The composition of the present invention is suitable particularly as astarting material for a laminated article which has anti-glaringproperty and low reflection and is used for suppressing lowering ofvisibility of an image in image displaying apparatuses such as a liquidcrystal display (LCD), a flat panel display (FPD), an organicelectroluminescent device (EL) and a plasma display (PDP).

The curing agent (b) in the composition of the present invention isoptionally selected depending on kind of the crosslinkable group (forexample, a hydrolyzable metal alkoxide moiety or a carbon-carbon doublebond) in the fluorine-containing polymer (a) (whether the group isradically reactive or cationically (acid) reactive), kind of activeenergy rays (wavelength range) to be used, intensity of irradiation, andthe like.

Generally examples of the initiator (photo-radical generator) for curingby using active energy rays in an ultraviolet region are, for instance,as follows.

Acetophenone Initiators

Acetophenone, chloroacetophenone, diethoxyacetophenone,hydroxyacetophenone, α-aminoacetophenone and the like.

Benzoin Initiators

Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropylether, benzoin isobutyl ether, benzyldimethylketal and the like.

Benzophenone Initiators

Benzophenone, benzoylbenzoic acid, methyl o-benzoylbenzoate,4-phenylbenzophenone, hydroxybenzophenone, hydroxy-propylbenzophenone,acrylated benzophenone, Michler's ketone and the like.

Thioxanthone Initiators

Thioxanthone, chlorothioxanthone, methylthioxanthone,diethylthioxanthone, dimethylthioxanthone and the like.

Other Initiators

Benzyl, α-acyloxime ester, acylphosphine oxide, glyoxyester,3-ketocoumaran, 2-ethylanthraquinone, camphorquinone, anthraquinone andthe like.

Also photo initiators such as amines, sulfones and sulfines may be addedas case demands.

Also examples of cationically (acid) reactive initiators (photoacidgenerators) are as follows.

Onium Salts

Iodonium salt, sulfonium salt, phosphonium salt, diazonium salt,ammonium salt, pyridinium salt and the like.

Sulfone Compounds

β-keto ester, β-sulfonyl sulfone, α-diazo compounds thereof and thelike.

Sulfonic Acid Esters

Alkyl sulfonate, haloalkyl sulfonate, aryl sulfonate, imino sulfonateand the like.

Others

Sulfonimide compounds, diazomethane compounds and the like.

In the curable fluorine-containing resin composition of the presentinvention, an adding amount of the curing initiator is optionallyselected depending on the content of crosslinkable group in thefluorine-containing polymer (I), further kinds of the initiator and theactive energy ray to be used, and an amount of irradiation energy(intensity and time). The amount of the curing initiator is from 0.01 to30 parts by mass, further from 0.05 to 20 parts by mass, most preferablyfrom 0.1 to 10 parts by mass based on 100 parts by mass of thefluorine-containing polymer (a).

To the curable fluorine-containing resin composition of the presentinvention may be blended various additives, as case demands, in additionto the above described compounds.

Examples of such additives are, for instance, a silane coupling agent, aplasticizer, a discoloration inhibitor, an antioxidant, an inorganicfiller, a leveling agent, a viscosity regulating agent, a lightstabilizer, a water absorbent, a pigment, a dye, a reinforcing agent andthe like.

Also to the composition of the present invention can be blended fineparticles or ultrafine particles of inorganic compounds for the purposesof increasing a hardness of a cured article and regulating a refractiveindex.

The fine particles of inorganic compound are not limited particularly,and preferred are compounds having a refractive index of not more than1.5. Specifically desirable are fine particles of magnesium fluoride(refractive index: 1.38), silicon oxide (refractive index: 1.46),aluminum fluoride (refractive index: 1.33 to 1.39), calcium fluoride(refractive index: 1.44), lithium fluoride (refractive index: 1.36 to1.37), sodium fluoride (refractive index: 1.32 to 1.34), thoriumfluoride (refractive index: 1.45 to 1.50) and the like. It is desirablethat a particle size of the fine particles is small enough as comparedwith a wavelength of visible light in order to secure transparency ofthe material having a low refractive index. Specifically the particlesize is not more than 100 nm, particularly preferably not more than 50nm.

In regulating the refractive index, it is possible to form a cavity withfine particles or ultrafine particles of the inorganic compound. Namely,in a coating film obtained using the composition of the presentinvention blended with fine particles or ultrafine particles of theinorganic compound, by use of this cavity, it is possible to make itsrefractive index lower as compared with a refractive index of a coatingfilm produced using no fine particles of inorganic compound.

When using the fine particles of inorganic compound, it is desirablethat the fine particles of inorganic compound are used in the form oforganic sol in which the fine particles have been previously dispersedin an organic dispersant in order not to lower dispersion stability inthe composition, adhesion in the low refractive index material and thelike. Further surfaces of the fine particles of inorganic compound canbe decorated previously with various coupling agents or the like inorder to enhance dispersion stability, adhesion in the low refractiveindex material and the like of the fine particles of inorganic compoundin the composition. Examples of the coupling agents are, for instance,organosilicon compounds; metal alkoxides such as aluminum, titanium,zirconium, antimony and a mixture thereof; salts of organic acid;coordination compounds having ligand; and the like.

In the fluorine-containing resin composition of the present inventionfor coating, the curable fluorine-containing polymer (a) or theadditives may be in the form of dispersion or solution in the solvent(c). Being in the form of uniform solution is preferred to form auniform thin coating film and also to enable the film to be formed atrelatively low temperature.

The present invention also relates to the curable fluorine-containingresin composition for coating obtained by blending a solvent to theabove-mentioned curable fluorine-containing resin composition

The solvent to be used is not limited particularly as long as thefluorine-containing polymer (a), the curing agent, and additives to beadded as case demands such as a leveling agent and a light stabilizerare uniformly dissolved or dispersed in it. Particularly preferred is asolvent dissolving the fluorine-containing polymer (a) uniformly.

Examples of the solvent are, for instance, cellosolve solvents such asmethyl cellosolve, ethyl cellosolve, methyl cellosolve acetate and ethylcellosolve acetate; ester solvents such as diethyl oxalate, ethylpyruvate, ethyl-2-hydroxybutyrate, ethyl acetoacetate, butyl acetate,amyl acetate, ethyl butyrate, butyl butyrate, methyl lactate, ethyllactate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl2-hydroxyisobutyrate and ethyl 2-hydroxyisobutyrate; propylene glycolsolvents such as propylene glycol monomethyl ether, propylene glycolmonoethyl ether, propylene glycol monobutyl ether, propylene glycolmonomethyl ether acetate, propylene glycol monoethyl ether acetate,propylene glycol monobutyl ether acetate and dipropylene glycol dimethylether; ketone solvents such as 2-hexanone, cyclohexanone, methyl aminoketone and 2-heptanone; alcohol solvents such as methanol, ethanol,propanol, isopropanol and butanol; aromatic hydrocarbons such as tolueneand xylene; solvent mixtures of two or more thereof and the like.

Also in order to enhance solubility of the fluorine-containing polymer(a), a fluorine-containing solvent may be used as case demands.

Examples of the fluorine-containing solvent are, for instance, CH₃CCl₂F(HCFC-141b), a mixture of CF₃CF₂CHCl₂ and CClF₂CF₂CHClF (HCFC-225),perfluorohexane, perfluoro(2-butyltetrahydrofuran),methoxy-nonafluorobutane, 1,3-bistrifluoromethylbenzene, and inaddition, fluorine-containing alcohols such as:

-   -   H(CF₂CF₂        _(n)CH₂OH (n: an integer of from 1 to 3),    -   F(CF₂        _(n)CH₂OH (n: an integer of from 1 to 5) and    -   CF₃CH(CF₃)OH,        benzotrifluoride, perfluorobenzene, perfluoro(tributylamine),        ClCF₂CFClCF₂CFCl₂ and the like.

Those fluorine-containing solvents may be used solely, in a mixturethereof or in a mixture of one or more of the fluorine-containingsolvents and non-fluorine-containing solvents.

Among them, ketone solvents, acetic acid ester solvents, alcoholsolvents and aromatic solvents are preferred from the viewpoint ofcoatability and productivity in coating.

The solid content of the coating composition is good enough as far ascoatability is good, a low molecular weight monomer component etc.hardly remain in the coating film after the curing and the surface ofthe coating film is free from tackiness. For example, the solid contentmay be selected within a range of the order of 0.5 to 10% by mass.

The curable fluorine-containing resin composition of the presentinvention is formed into a cured article or a cured film by curing, forexample, by photocuring, and can be applied to various substrates andcan be used to various applications.

Kind of a product, namely kind of a substrate which is provided with alow reflection by means of the cured article or the cured film is notlimited particularly. Examples of the substrate are, for instance,inorganic materials such as glass, stone, concrete and tile; metals suchas iron, aluminum and copper; wood, paper, printed matter, printingpaper, picture and the like.

Further there are synthetic resins such as a vinyl chloride resin,polyethylene terephthalate, cellulose resin such as triacetyl cellulose,polycarbonate resin, polyolefin resin, acrylic resin, phenol resin,xylene resin, urea resin, melamine resin, diallyl phthalate resin, furanresin, amino resin, alkyd resin, urethane resin, vinyl ester resin,polyimide resin and polyamide resin.

When a certain portion of the product other than a specific portionthereof is provided with the laminated article and the shape of thespecific portion is lifted up by a reflecting light, a decorative effectof the article can be enhanced.

Among the substrates, an anti-glaring substrate for liquid crystaldisplay (LCD) has a surface coated with fine inorganic particles, and isused preferably and as a result, can effectively exhibit anti-glaringproperty and a low reflection effect.

The composition of the present invention is effectively applied on thefollowing articles.

Optical parts such as prism, lens sheet, polarizing plate, opticalfilter, lenticular lens, Fresnel lens, screen of rear projectiondisplay, lens for reduction projection type exposure meter, opticalfiber and optical coupler; transparent protection plates represented byglass for show window, glass for show case, a cover for advertisementand a cover for photo-stand; protection plates for CRT, liquid crystaldisplay, plasma display and rear projection display; optical recordingmedia represented by optical magnetic disk, read-only type optical diskssuch as CD•LD•DVD, phase transition type optical disk such as PD andhologram recording; photolithography-related members for production ofsemiconductors such as photoresist, photomask, pellicle and reticule;protection covers for light emitters such as halogen lamp, fluorescentlamp and incandescent lamp; and sheet or film for adhering to theabove-mentioned articles.

The composition of the present invention is also effectively applied asa sealing agent on the following articles.

Photo-semiconductor, i.e. light emission devices such as LED;photodetectors such as photo transistor, photo diode and CCD; andsemiconductor devices (photo-semiconductor device) such as EPROM.

Further the composition of the present invention is also effective as anadhesive when applied to articles in the form mentioned below.

Tape and substrate for a carrier of semiconductor device, lead frame,wiring board and wiring sheet such as printed circuit board and moduleboard, and further a surface layer of a substrate for package and asurface of interlayer insulation.

EXAMPLES

The present invention is then explained by means of Examples andSynthesis Examples, but is not limited to those Examples.

The methods of measuring various physical properties and parameters usedin the present invention are collectively explained below.

(1) NMR

Measuring equipment of NMR: available from BRUCKER CO., LTD.

Measuring conditions of ¹H-NMR: 300 MHz (tetramethylsilane=0 ppm)

Measuring conditions of ¹⁹F-NMR: 282 MHz (trichlorofluoromethane=0 ppm)

(2) IR Analysis

Measuring is carried out at room temperature with a Fourier-transforminfrared spectrophotometer 1760X available from Perkin Elmer Co., Ltd.

(3) Fluorine Content

The fluorine content (% by mass) is obtained by burning 10 mg of asample by an oxygen flask combustion method, absorbing cracked gas in 20ml of de-ionized water and then measuring a fluorine ion concentrationin the fluorine ion-containing solution through fluoride-ion selectiveelectrode method (using a fluorine ion meter model 901 available fromOrion).

Example 1 Synthesis of Fluorine-Containing Allyl Ether Monomer HavingSilicon Alkoxide

Into a 100 ml four-necked glass flask equipped with a stirrer and athermometer were poured 20.0 g ofperfluoro-(1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxanonenol):

10.0 g of γ-isocyanatepropyltrimethoxysilane (a ratio toperfluoro-[1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxanonenol]:1.0 e.q.), 20 ml of tetrahydrofuran (THF) as a reaction solvent, and0.01 g of di-n-butyltin laurate (a ratio toγ-isocyanatepropyltrimethoxysilane:0.10 mass %), followed by reactionwith stirring at 45° C. for two hours. After completion of the reaction,the reaction solvent was distilled off with an evaporator, and IRanalysis was carried out.

Since —OH group ofperfluoro-[1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxanonenol]disappeared and a urethane bond (—OCONH—) was produced and also since anabsorption peak derived from a silicon alkoxide (—SiOR—) was observed,the obtained reaction product was a fluorine-containing allyl ethermonomer:

having silicon alkoxide. An IR chart is shown in FIG. 1.

Example 2 Synthesis of Polymer Comprising Fluorine-Containing AllylEther Having Silicon Alkoxide

Into a 100 ml four-necked glass flask equipped with a stirrer and athermometer were poured 20.1 g of the fluorine-containing allyl ethermonomer having silicon alkoxide and obtained in Example 1, 20.4 g ofperfluoro-(1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxanonenol):

and 21.2 g of 8.0% by weight perfluorohexane solution of:

H(CF₂CF₂

₃COO

₂and after sufficiently replacing the inside of the flask with nitrogen,stirring was carried out at 20° C. for 24 hours in a nitrogen gasstream, and a highly viscose solid was produced.

The obtained solid was dissolved in diethyl ether and poured intoperfluorohexane, followed by separation and vacuum drying to obtain 35.2g of a colorless transparent polymer.

According to ¹⁹F-NMR analysis, ¹H-NMR analysis and IR analysis, thispolymer was a copolymer comprising a fluorine-containing allyl etherhaving OH group and a fluorine-containing allyl ether having —Si(OR)₃group in a percent by mole ratio of 50:50.

Also according to GPC analysis using tetrahydrofuran (THF) as a solvent,a number average molecular weight of the polymer was 9,000, and a weightaverage molecular weight thereof was 22,000.

Example 3 Synthesis of Curable Fluorine-Containing Polymer HavingSilicon Alkoxide and α-fluoroacryloyl Group

Into a 200 ml four-necked flask equipped with a reflux condenser, athermometer, a stirrer and a dropping funnel were poured 80 ml ofdiethyl ether, 5.0 g of the polymer containing fluorine-containing allylether having silicon alkoxide and obtained in Example 2, and 1.0 g ofpyridine, followed by cooling to 5° C. or lower with ice.

While stirring in a nitrogen gas stream, a solution prepared bydissolving 1.0 g of α-fluoroacrylic acid fluoride: CH₂═CFCOF in 20 ml ofdiethyl ether was further added dropwise over about 30 minutes.

After completion of the addition, the temperature of the mixture wasincreased to room temperature, and stirring was continued for another4.0 hours.

The ether solution after the reaction was poured into the droppingfunnel, and after repeating washing with water, 2% hydrochloric acidsolution, 5% NaCl solution and then water, was dried with anhydrousmagnesium sulfate, and then the ether solution was separated byfiltration.

According to ¹⁹F-NMR analysis, this ether solution was a copolymercomprising a fluorine-containing allyl ether having OCOCF═CH₂ group, afluorine-containing allyl ether having OH group, and afluorine-containing allyl ether having —Si(OR)₃ group in a percent bymole ratio of 40:10:50.

The obtained copolymer was coated on a silicon wafer, and formed into acast film at room temperature. According to IR analysis of the castfilm, an absorption of carbon-carbon double bond was observed at 1,661cm⁻¹, an absorption of C═O group, at 1,770 cm⁻¹, and an absorption ofSi(OCH₃)₃ group, at 1,100 cm⁻¹. An IR chart is shown in FIG. 2.

Example 4 (1) Preparation of Fluorine-Containing Resin Composition forCoating

To the curable fluorine-containing polymer (ether solution) havingsilicon alkoxide and α-fluoroacryloyl group and obtained in Example 3was added methyl isobutyl ketone (MIBK), and then ether was distilledoff with an evaporator to adjust the polymer concentration to 3.75% byweight.

To 10 g of the obtained polymer solution was added 1.7 g of a solutionprepared by dissolving2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one as an activeenergy curing initiator in MIBK in a concentration of 1% by weight.

Example 5 (1) Preparation of Fluorine-Containing Resin Composition forCoating

A fluorine-containing resin composition for coating containing nosilicon alkoxide was prepared in the same manner as in Example 4 exceptthat the fluorine-containing allyl ether having —Si(OR)₃ group was notcontained in the fluorine-containing resin composition prepared by meansof Examples 2 to 4.

(2) Production of Laminated Article

The above-mentioned coating composition was applied to an un-coated PETfilm subjected to anti-glaring treatment with an applicator, and driedat 25° C. for five minutes.

(Light Irradiation)

The dried coating film was irradiated with ultraviolet light at anintensity of 3,000 mJ/cm²U at room temperature using a high pressuremercury lamp.

(3) Measurement of Refractive Index of Curable Fluorine-ContainingPolymer

The 3.75% MIBK solution of the curable fluorine-containing polymer (thepolymer solution before adding the curing catalyst in theabove-mentioned (1) of Examples 4 and 5) was coated on a PET film withan applicator so that a coating thickness after the drying became about100 μm. After drying at 50° C. for 10 minutes, an obtained cast film waspeeled from the PET film, and a refractive index thereof was measuredusing an Abbe's refractometer at 25° C. with light having a wavelengthof 550 nm. The results are shown in Table 1.

(4) Measurement of Refractive Index of Cured Film

The coating compositions prepared in the above-mentioned (1) of Examples4 and 5 were coated on an aluminum foil with an applicator so that acoating thickness became about 100 μm, followed by drying at 50° C. for10 minutes. After the dried coating film was subjected to irradiation oflight in the same manner as in (2) above, the aluminum foil was moltenwith diluted hydrochloric acid to make a sample film. A refractive indexof the obtained cured film was measured in the same manner as in (3)above. The results are shown in Table 1.

(5) Evaluation of Physical Properties of Laminated Article

The following physical properties of the laminated article obtained in(2) above were evaluated. The results are shown in Table 1.

(5-1) Dry to Touch

Tackiness was evaluated by touching with fingers according to JIS K4500.

The evaluation is made by:

◯: There is no tackiness.

X: There is tackiness.

(5-2) Pencil Hardness

Measured according to JIS K5400.

(5-3) Solvent Resistance

After the surface of the coating film is rubbed with a cotton clothimpregnated with acetone, condition (dissolved or peeled) of the coatingfilm surface is evaluated.

When there is no change, it is evaluated as ◯, and when there isdissolution or peeling, it is evaluated as X.

(5-4) Abrasion Resistance Test

A cotton cloth (BEMCOT (Registered trademark) M-3 available from AsahiChemical Co., Ltd.) is fitted to a rubbing tester, and the laminatedarticle is rubbed by 100 rubbing cycles at a load of 100 gf/cm². Thenthe condition of the film is observed.

The evaluation is made as follows.

◯: There is no change.

Δ: A flaw is found partly.

X: There is a portion where a film is peeled and a substrate is seen.

(5-5) Measurement of Reflectance of One Side of Film

A PET film provided with the laminated article was set on a thin filmreflectance meter F-20 (available from Filmetrics Co.), and areflectance was measured with light having a wavelength of 550 nm.

Comparative Example 1

A one side reflection of an un-coated PET film subjected to anti-glaringtreatment was measured, and the results thereof are shown in Table 1.

TABLE 1 Example 4 Example 5 Com. Ex. 1 Substrate film Anti-glare PETAnti-glare PET Anti-glare PET Curable fluorine- Example 3 Un-coatedcontaining polymer Content of 40 50 —O(C═O)CF═CH₂ group (% by mole)Solvent MIBK MIBK Concentration of 3.75 3.75 polymer (% by weight)Active energy curing Curing Curing initiator initiator 1 initiator 1Ratio to polymer 3 3 (% by weight) Amount of ultraviolet 4200 4200 light(mJ/cm) Refractive index Before curing 1.380 1.367 After curing 1.3871.375 Dry to touch ◯ ◯ Un-coated Solvent resistance ◯ X Abrasionresistance ◯ X Reflectance on 4.82 4.70 8.00 one side of film (%) Curinginitiator 1: 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one

INDUSTRIAL APPLICABILITY

The present invention can provide a material which is free from fadinginto white due to surface scattering while maintaining anti-glaringproperty and is useful as a laminated article having excellent adhesionand practical low reflection.

1. A curable fluorine-containing polymer having a hydrolyzable metalalkoxide moiety which has a number average molecular weight of from 500to 1,000,000 and is represented by the formula (2):

M

N

A

  (2)

M

N

A

  (2) wherein the structural unit M is a structural unit derived from afluorine-containing ethylenic monomer having a hydrolyzable metalalkoxide moiety and represented by the formula (M):

in which X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf¹ is represented by the formula:—D—Ry wherein —D— is a fluoroether unit represented by the formula (D):

O—R

_(n) or

R—O

_(n)  (D) in which n is an integer of 1 to 20; R is at least oneselected from fluorine-containing divalent alkylene groups having 1 to 5carbon atoms where at least one of hydrogen atoms is replaced byfluorine atom, and R may be the same or different when n is not lessthan two; Ry is a hydrocarbon group having 1 to 39 carbon atoms where apart or the whole of hydrogen atoms are may be replaced by fluorineatoms or a hydrocarbon group having 1 to 99 carbon atoms and ether bondwhere a part or the whole of hydrogen atoms are may be replaced byfluorine atoms, which is an organic group in which one to three ofhydrogen atoms are replaced by Y¹ where Y¹ is a functional group having,at its end, at least one hydrolyzable metal alkoxide moiety having 1 to50 carbon atoms; Ry may contain —CONH— bond; a is 0 or an integer of 1to 3; b and c are the same or different, and each is 0 or 1, thestructural unit N is a structural unit derived from afluorine-containing ethylenic monomer and represented by the formula(N):

in which X¹ and X² are the same or different, and each is H or F; X³ isH, F, CH₃ or CF₃; X⁴ and X⁵ are the same or different, and each is H, For CF₃; Rf² is a fluorine-containing alkyl group having 1 to 40 carbonatoms or a fluorine-containing alkyl group having 2 to 100 carbon atomsand ether bond, which is an organic group in which 1 to 3 hydrogen atomsare replaced by Y² where Y² is a monovalent organic group having 2 to 10carbon atoms and having, at its end, an ethylenic carbon-carbon doublebond; a is 0 or an integer of 1 to 3; b and c are the same or different,and each is 0 or 1, the structural unit A is a structural unit derivedfrom a monomer being copolymerizable with the fluorine-containingethylenic monomers providing the structural units represented by theformulae (M) and (N), and the structural units M, N and A are containedin amounts of from 0.1 to 100% by mole, from 0 to 99.9% by mole and from0 to 99.9% by mole, respectively, wherein the formula (2), thestructural unit M is a structural unit M1 derived from afluorine-containing ethylenic monomer and represented by the formula(M1):

wherein X¹, X², X³, X⁴, X⁵, Rf¹, a and c are as defined above.
 2. Thecurable fluorine-containing polymer of claim 1, wherein at least one ofY¹ bonded to an end is a terminal part of Rf¹.
 3. The curablefluorine-containing polymer of claim 1, wherein in the formula (2), thestructural unit M is a structural unit M1 derived from afluorine-containing ethylenic monomer and represented by the formula(M1):

wherein X¹, X², X³, X⁴, X⁵, Rf¹, a and c are as defined above.
 4. Thecurable fluorine-containing polymer of claim 1, wherein in the formula(2), the structural unit M is a structural unit M2 derived from afluorine-containing ethylenic monomer and represented by the formula(M2):

wherein Rf¹ is as defined above.
 5. The curable fluorine-containingpolymer of claim 1, wherein in the formula (2), the structural unit M isa structural unit M3 derived from a fluorine-containing ethylenicmonomer and represented by the formula (M3):

wherein Rf¹ is as defined above.
 6. The curable fluorine-containingpolymer of claim 1, wherein Ry is a group represented by the formula(Ry):—O—Ry¹  (Ry) wherein Ry¹ is an organic-inorganic complex radicalrepresented by the formula:—(R¹¹)_(p)R¹²—(Y^(1a))_(m) where p is 0 or 1; m is an integer of 1 to 3;R¹¹ is —CONH—; R¹² is a di-, tri- or tetra-valent hydrocarbon grouphaving 1 to 39 carbon atoms where a part or the whole of hydrogen atomsare may be replaced by fluorine atoms or a di-, tri- or tetra-valenthydrocarbon group having 1 to 99 carbon atoms and ether bond where apart or the whole of hydrogen atoms are may be replaced by fluorineatoms; Y^(1a) is a functional group represented by the formula:—[M¹O(R²⁹)_(a)(R³⁰)_(b)(R³¹)_(c)(R³²)_(d)]_(n)—M²(R³³)_(e)(R³⁴)_(f)(R³⁵)_(g)(R³⁶)_(h)(R³⁷)_(i)where M¹ and M² are the same or different and each is a di-, tri-,tetra-, penta- or hexa-valent metal atom; a, b, c and d are 0 or 1, anda+b+c+d+2 is equal to the number of valences of the metal atom M¹; e, f,g, h and i are 0 or 1, and e+f+g+h+i+1 is equal to the number ofvalences of the metal atom M²; R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶and R³⁷ are the same or different and each is an organic grouprepresented by the formula: OR³⁸ or R³⁸ where R³⁸ is hydrogen atom or ahydrocarbon group having 1 to 10 carbon atoms in which a part or thewhole of hydrogen atoms may be replaced by fluorine atoms, and at leastone of R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶ and R³⁷ is OR³⁸; n is 0 oran integer of 1 to
 11. 7. A curable fluorine-containing resincomposition comprising: (a) the curable fluorine-containing polymerhaving a hydrolyzable metal alkoxide moiety of claim 1, and (b) a curingagent.
 8. A cured article obtained by curing the curablefluorine-containing resin composition of claim
 7. 9. A curablefluorine-containing resin composition for coating comprising: (a) thecurable fluorine-containing polymer having a hydrolyzable metal alkoxidemoiety of claim 1, (b) a curing agent, and (c) a solvent.
 10. A curedcoating film obtained by curing a coating film formed by applying thecurable fluorine-containing resin composition for coating of claim 9.